how to display only time in UIDatePicker iphone

In my app i am displaying a UIDateTimePicker in action sheet through code. it is working fine. But i don't want to display date and day.How this can be done. Please help. Thanks in advance.

code:

UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:NSLocalizedString(@"Select     Date",@"Selecte Date")delegate:self cancelButtonTitle:NSLocalizedString(@"Done",@"Done")
destructiveButtonTitle:NSLocalizedString(@"Cancel",@"Cancel")
otherButtonTitles:nil];  


    actionSheet.actionSheetStyle = UIActionSheetStyleBlackTranslucent;
  UIDatePicker  *datePicker = [[UIDatePicker alloc] initWithFrame:CGRectMake(0, 50, 320, 270)];
    //datePicker.showsSelectionIndicator = YES;
//   datePicker.dataSource = self;
//datePicker.delegate = self;
    [actionSheet addSubview:datePicker];
    [datePicker release];

    [actionSheet showInView:self.view];
    [actionSheet setBounds:CGRectMake(0, 0, 320, 500)];
  [actionSheet release];

datePicker.datePickerMode = UIDatePickerModeTime;